Article summary

Summary

Discusses how to create an AEM project by using Maven Adobe Archetype 10.  

A special thank you to Ratna Kumar Kotla, an AEM community member, for contributing towards this article by testing the content.

This article covers the following development tasks: 

  • how to use Maven Archetype 10 command to create an AEM project
  • how to use HTML Template Language (HTL- formerly known as Sightly) and Sling Models
  • how to use JUNIT tests within Java files
  • how to use a scheduler service
  • how to use Sling Servlets
  • how to use a basic event handler
  • how to perform component inheritence
  • how to reference partial page files in a HTL page component
  • how to work with ClientLibs in a HTL component

Note: HTL is the AEM template language that can be used to replace use of JSP when developing an AEM component. HTL helps you to separate your design from your application logic. For more information, see Introduction to the HTML Template Language.

Digital Marketing Solution(s) Adobe Experience Manager (Adobe CQ)
Audience
Developer (intermediate)
Required Skills
Java, OSGi, Maven
Tested On AEM 6.2

Introduction

You can create an AEM 6.2 project by using Adobe Maven Archetype 10. This development article walks you through creating an AEM 6.2 project by using Archetype 10 and explains the default AEM files and services. Using an Archetype 10 project, you are given a set of files to start with:

2 Pages

  • English and French pages with filler text

2 Templates

  • For homepage and content pages
  • Homepages are only allowed on top level, and content pages below

Page component

  • Built with HTL templates and simple server-side JavaScript logic
  • The CSS class on the body element changes based on page template
  • Internationalized footer text as example

Structure Components

  • Topnav: simple custom HTL component
  • Logo: based on foundation

Content Components

  • helloworld: example of custom HTL component with SlingModels for the logic 
  • colctrl, textimage, text, image,
  • title: use the HTL foundation components

Configurations

  • Device emulators displayed in the authoring interface
  • Allow direct drag & drop of assets from the content finder into parsys (6.1 TouchUI)
    Dictionnary structure for internationalizing hardcoded strings

Client libraries

  • Responsive layout with colctr that break for narrow pages
  • CSS class names follow AEM naming conventions
  • Component-specific styles stored within each component
  • Master ClientLib under /etc/designs merges all client libraries into one file

Bundle with some examples

  • Models: Models for more complex business logic of components
  • Servlets: Rendering the output of specific requests
  • Filters: Applied to the requests before dispatching to the servlet or script
  • Schedulers: Cron-job like tasks

Tests

  • Unit tests
  • Integration tests
  • Client-side Hobbes tests within developer mode

The following illustration represents a default AEM page that is created by the Archetype 10 project.

Intro10
A default page created by Maven Archetype 10

Setup Maven in your development environment

You can use Maven to build an OSGi bundle that contains a Sling Servlet. Maven manages required JAR files that a Java project needs in its class path. Instead of searching the Internet trying to find and download third-party JAR files to include in your project’s class path, Maven manages these dependencies for you.

You can download Maven 3 from the following URL:

http://maven.apache.org/download.html

After you download and extract Maven, create an environment variable named M3_HOME. Assign the Maven install location to this environment variable. For example:

C:\Programs\Apache\apache-maven-3.0.4

Set up a system environment variable to reference Maven. To test whether you properly setup Maven, enter the following Maven command into a command prompt:

%M3_HOME%\bin\mvn -version

This command provides Maven and Java install details and resembles the following message:

Java home: C:\Programs\Java64-6\jre
Default locale: en_US, platform encoding: Cp1252
OS name: "windows 7", version: "6.1", arch: "amd64", family: "windows"

Note:

It is recommended that you use Maven 3.0.3 or greater. For more information about setting up Maven and the Home variable, see: Maven in 5 Minutes.

Next, copy the Maven configuration file named settings.xml from [install location]\apache-maven-3.0.4\conf\ to your user profile. For example, C:\Users\scottm\.m2\.

You have to configure your settings.xml file to use Adobe’s public repository. For information, see Adobe Public Maven Repository at http://repo.adobe.com/.

The following XML code represents a settings.xml file that you can use.

<?xml version="1.0" encoding="UTF-8"?>

<!--
Licensed to the Apache Software Foundation (ASF) under one
or more contributor license agreements.  See the NOTICE file
distributed with this work for additional information
regarding copyright ownership.  The ASF licenses this file
to you under the Apache License, Version 2.0 (the
"License"); you may not use this file except in compliance
with the License.  You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing,
software distributed under the License is distributed on an
"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
KIND, either express or implied.  See the License for the
specific language governing permissions and limitations
under the License.
-->

<!--
 | This is the configuration file for Maven. It can be specified at two levels:
 |
 |  1. User Level. This settings.xml file provides configuration for a single user, 
 |                 and is normally provided in ${user.home}/.m2/settings.xml.
 |
 |                 NOTE: This location can be overridden with the CLI option:
 |
 |                 -s /path/to/user/settings.xml
 |
 |  2. Global Level. This settings.xml file provides configuration for all Maven
 |                 users on a machine (assuming they're all using the same Maven
 |                 installation). It's normally provided in 
 |                 ${maven.home}/conf/settings.xml.
 |
 |                 NOTE: This location can be overridden with the CLI option:
 |
 |                 -gs /path/to/global/settings.xml
 |
 | The sections in this sample file are intended to give you a running start at
 | getting the most out of your Maven installation. Where appropriate, the default
 | values (values used when the setting is not specified) are provided.
 |
 |-->
<settings xmlns="http://maven.apache.org/SETTINGS/1.0.0" 
          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
          xsi:schemaLocation="http://maven.apache.org/SETTINGS/1.0.0 http://maven.apache.org/xsd/settings-1.0.0.xsd">
  <!-- localRepository
   | The path to the local repository maven will use to store artifacts.
   |
   | Default: ~/.m2/repository
  <localRepository>/path/to/local/repo</localRepository>
  -->

  <!-- interactiveMode
   | This will determine whether maven prompts you when it needs input. If set to false,
   | maven will use a sensible default value, perhaps based on some other setting, for
   | the parameter in question.
   |
   | Default: true
  <interactiveMode>true</interactiveMode>
  -->

  <!-- offline
   | Determines whether maven should attempt to connect to the network when executing a build.
   | This will have an effect on artifact downloads, artifact deployment, and others.
   |
   | Default: false
  <offline>false</offline>
  -->

  <!-- pluginGroups
   | This is a list of additional group identifiers that will be searched when resolving plugins by their prefix, i.e.
   | when invoking a command line like "mvn prefix:goal". Maven will automatically add the group identifiers
   | "org.apache.maven.plugins" and "org.codehaus.mojo" if these are not already contained in the list.
   |-->
  <pluginGroups>
    <!-- pluginGroup
     | Specifies a further group identifier to use for plugin lookup.
    <pluginGroup>com.your.plugins</pluginGroup>
    -->
  </pluginGroups>

  <!-- proxies
   | This is a list of proxies which can be used on this machine to connect to the network.
   | Unless otherwise specified (by system property or command-line switch), the first proxy
   | specification in this list marked as active will be used.
   |-->
  <proxies>
    <!-- proxy
     | Specification for one proxy, to be used in connecting to the network.
     |
    <proxy>
      <id>optional</id>
      <active>true</active>
      <protocol>http</protocol>
      <username>proxyuser</username>
      <password>proxypass</password>
      <host>proxy.host.net</host>
      <port>80</port>
      <nonProxyHosts>local.net|some.host.com</nonProxyHosts>
    </proxy>
    -->
  </proxies>

  <!-- servers
   | This is a list of authentication profiles, keyed by the server-id used within the system.
   | Authentication profiles can be used whenever maven must make a connection to a remote server.
   |-->
  <servers>
    <!-- server
     | Specifies the authentication information to use when connecting to a particular server, identified by
     | a unique name within the system (referred to by the 'id' attribute below).
     | 
     | NOTE: You should either specify username/password OR privateKey/passphrase, since these pairings are 
     |       used together.
     |
    <server>
      <id>deploymentRepo</id>
      <username>repouser</username>
      <password>repopwd</password>
    </server>
    -->
    
    <!-- Another sample, using keys to authenticate.
    <server>
      <id>siteServer</id>
      <privateKey>/path/to/private/key</privateKey>
      <passphrase>optional; leave empty if not used.</passphrase>
    </server>
    -->
  </servers>

  <!-- mirrors
   | This is a list of mirrors to be used in downloading artifacts from remote repositories.
   | 
   | It works like this: a POM may declare a repository to use in resolving certain artifacts.
   | However, this repository may have problems with heavy traffic at times, so people have mirrored
   | it to several places.
   |
   | That repository definition will have a unique id, so we can create a mirror reference for that
   | repository, to be used as an alternate download site. The mirror site will be the preferred 
   | server for that repository.
   |-->
  <mirrors>
    <!-- mirror
     | Specifies a repository mirror site to use instead of a given repository. The repository that
     | this mirror serves has an ID that matches the mirrorOf element of this mirror. IDs are used
     | for inheritance and direct lookup purposes, and must be unique across the set of mirrors.
     |
    <mirror>
      <id>mirrorId</id>
      <mirrorOf>repositoryId</mirrorOf>
      <name>Human Readable Name for this Mirror.</name>
      <url>http://my.repository.com/repo/path</url>
    </mirror>
     -->
  </mirrors>
  
  <!-- profiles
   | This is a list of profiles which can be activated in a variety of ways, and which can modify
   | the build process. Profiles provided in the settings.xml are intended to provide local machine-
   | specific paths and repository locations which allow the build to work in the local environment.
   |
   | For example, if you have an integration testing plugin - like cactus - that needs to know where
   | your Tomcat instance is installed, you can provide a variable here such that the variable is 
   | dereferenced during the build process to configure the cactus plugin.
   |
   | As noted above, profiles can be activated in a variety of ways. One way - the activeProfiles
   | section of this document (settings.xml) - will be discussed later. Another way essentially
   | relies on the detection of a system property, either matching a particular value for the property,
   | or merely testing its existence. Profiles can also be activated by JDK version prefix, where a 
   | value of '1.4' might activate a profile when the build is executed on a JDK version of '1.4.2_07'.
   | Finally, the list of active profiles can be specified directly from the command line.
   |
   | NOTE: For profiles defined in the settings.xml, you are restricted to specifying only artifact
   |       repositories, plugin repositories, and free-form properties to be used as configuration
   |       variables for plugins in the POM.
   |
   |-->
  <profiles>
    <!-- profile
     | Specifies a set of introductions to the build process, to be activated using one or more of the
     | mechanisms described above. For inheritance purposes, and to activate profiles via <activatedProfiles/>
     | or the command line, profiles have to have an ID that is unique.
     |
     | An encouraged best practice for profile identification is to use a consistent naming convention
     | for profiles, such as 'env-dev', 'env-test', 'env-production', 'user-jdcasey', 'user-brett', etc.
     | This will make it more intuitive to understand what the set of introduced profiles is attempting
     | to accomplish, particularly when you only have a list of profile id's for debug.
     |
     | This profile example uses the JDK version to trigger activation, and provides a JDK-specific repo.
    <profile>
      <id>jdk-1.4</id>

      <activation>
        <jdk>1.4</jdk>
      </activation>

      <repositories>
        <repository>
          <id>jdk14</id>
          <name>Repository for JDK 1.4 builds</name>
          <url>http://www.myhost.com/maven/jdk14</url>
          <layout>default</layout>
          <snapshotPolicy>always</snapshotPolicy>
        </repository>
      </repositories>
    </profile>
    -->

    <!--
     | Here is another profile, activated by the system property 'target-env' with a value of 'dev',
     | which provides a specific path to the Tomcat instance. To use this, your plugin configuration
     | might hypothetically look like:
     |
     | ...
     | <plugin>
     |   <groupId>org.myco.myplugins</groupId>
     |   <artifactId>myplugin</artifactId>
     |   
     |   <configuration>
     |     <tomcatLocation>${tomcatPath}</tomcatLocation>
     |   </configuration>
     | </plugin>
     | ...
     |
     | NOTE: If you just wanted to inject this configuration whenever someone set 'target-env' to
     |       anything, you could just leave off the <value/> inside the activation-property.
     |
    <profile>
      <id>env-dev</id>

      <activation>
        <property>
          <name>target-env</name>
          <value>dev</value>
        </property>
      </activation>

      <properties>
        <tomcatPath>/path/to/tomcat/instance</tomcatPath>
      </properties>
    </profile>
    -->
  

<profile>

                <id>adobe-public</id>

                <activation>

                    <activeByDefault>true</activeByDefault>

                </activation>

                <repositories>

                  <repository>

                    <id>adobe</id>

                    <name>Nexus Proxy Repository</name>

                    <url>http://repo.adobe.com/nexus/content/groups/public/</url>

                    <layout>default</layout>

                  </repository>

                </repositories>

                <pluginRepositories>

                  <pluginRepository>

                    <id>adobe</id>

                    <name>Nexus Proxy Repository</name>

                    <url>http://repo.adobe.com/nexus/content/groups/public/</url>

                    <layout>default</layout>

                  </pluginRepository>

                </pluginRepositories>

            </profile>

</profiles>

  <!-- activeProfiles
   | List of profiles that are active for all builds.
   |
  <activeProfiles>
    <activeProfile>alwaysActiveProfile</activeProfile>
    <activeProfile>anotherAlwaysActiveProfile</activeProfile>
  </activeProfiles>
  -->
</settings>

Note:

The Adobe repository URL is now made secured. Change http://repo.adobe.com/nexus/content/groups/public/ to https://repo.adobe.com/nexus/content/groups/public/.

Create an Adobe CQ archetype project

You can create an AEM archetype 10 project by using the Maven archetype plugin. In this example, assume that the working directory is C:\AdobeCQ. 

files
Default files created by the Adobe Maven Archetype 10

Archetype 10 arguments

The following list describes the Archetype 10 project arguments: 

  • groupId - Base Maven groupId
  • artifactId - Base Maven ArtifactId
  • version - the version of your project
  • package - Java Source Package
  • appsFolderName - /apps folder name
  • artifactName - Maven Project Name
  • componentGroupName - AEM component group name
  • contentFolderName - /content folder name
  • cssId - prefix used in generated css
  • packageGroup - Content Package Group name
  • siteName - AEM site name

Create an Archetype 10 project

To create an AEM archetype 10 project, perform these steps:

1. Open the command prompt and go to your working directory (for example, C:\AdobeCQ).

2. Run the following Maven command:

mvn archetype:generate -DarchetypeGroupId=com.adobe.granite.archetypes -DarchetypeArtifactId=aem-project-archetype -DarchetypeVersion=10 -DarchetypeRepository=https://repo.adobe.com/nexus/content/groups/public/

3. When prompted, specify the following information:  

  • groupId - AEM62App 
  • artifactId - echo62
  • version - 1.0-SNAPSHOT
  • package - com.aem.community
  • appsFolderName - AEM62App  
  • artifactName - AEM62App 
  • componentGroupName - AEM62
  • contentFolderName - AEM62App 
  • cssId - AEM62CSS
  • packageGroup -AEM62App 
  • siteName - AEM62App 

4. WHen prompted, specify Y.

5. Once done, you will see a message like:

[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 01:42 min
[INFO] Finished at: 2016-04-25T14:34:19-04:00
[INFO] Final Memory: 16M/463M
[INFO] ------------------------------------------------------------------------

6. Change the working directory to echo62 and then enter the following command. 

mvn eclipse:eclipse

After you run this command, you can import the project into Eclipse as discussed in the next section.

Import the project into Eclipse 

To make it easier to work with the Maven generated project, import it into the Eclipse development environment, as shown in the following illustration. 

projectFiles
Default project files created by using a Maven Archetype 10 project

Note:

Do not worry about the errors reported in Eclipse. It does not read the POM file where the APIs are resolved. You build the bundle with Maven. Eclipse is used to edit the Java files and the POM file.

After you import the project into Eclipse, notice each module is a separate Eclipse project: 

  • core - where Java files that are used in OSGi services and sling servlets are located
  • launcher - where additional Java files are located
  • tests - Java files for tests like JUNIT tests
  • apps - content under /apps
  • content - content under /content

When you want to create an OSGi service, you work under core. Likewise, if you want to create a HTL component, you can work under apps

By default, the Archetype 10 project creates a number of Java files that you can use as a starting point in your project (these Java files are located under core).

The following illustration shows the packages. 

JavaFiles
Default Java source files

TestHelloWorldModel class

The TestHelloWorldModel is used to perform JUNIT tests.  This class uses the @Test annotation to perform a test. The following code represents this class. 

package com.aem.community.core.models;

import static org.junit.Assert.assertNotNull;
import static org.junit.Assert.assertTrue;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.when;

import java.util.UUID;

import junitx.util.PrivateAccessor;

import org.apache.sling.settings.SlingSettingsService;
import org.junit.Before;
import org.junit.Test;

/**
 * Simple JUnit test verifying the HelloWorldModel
 */
public class TestHelloWorldModel {

    //@Inject
    private HelloWorldModel hello;
    
    private String slingId;
    
    @Before
    public void setup() throws Exception {
        SlingSettingsService settings = mock(SlingSettingsService.class);
        slingId = UUID.randomUUID().toString();
        when(settings.getSlingId()).thenReturn(slingId);

        hello = new HelloWorldModel();
        PrivateAccessor.setField(hello, "settings", settings);
        hello.init();
    }
    
    @Test
    public void testGetMessage() throws Exception {
        // some very basic junit tests
        String msg = hello.getMessage();
        assertNotNull(msg);
        assertTrue(msg.length() > 0);
    }

}

LoggingFilter class

The LoggingFilter class performs a simple servlet filter operation that logs incoming requests. This class uses the @SlingFilter annotation that supports filter processing by applying filter chains requests before dispatching to the servlet for processing. For more information, see Servlet Filter Support

The following code represents this class. 

package com.aem.community.core.filters;

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;

import org.apache.felix.scr.annotations.sling.SlingFilter;
import org.apache.felix.scr.annotations.sling.SlingFilterScope;
import org.apache.sling.api.SlingHttpServletRequest;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Simple servlet filter component that logs incoming requests.
 */
@SlingFilter(order = -700, scope = SlingFilterScope.REQUEST)
public class LoggingFilter implements Filter {

    private final Logger logger = LoggerFactory.getLogger(getClass());

    @Override
    public void doFilter(final ServletRequest request, final ServletResponse response,
            final FilterChain filterChain) throws IOException, ServletException {

        final SlingHttpServletRequest slingRequest = (SlingHttpServletRequest) request;
        logger.debug("request for {}, with selector {}", slingRequest
                .getRequestPathInfo().getResourcePath(), slingRequest
                .getRequestPathInfo().getSelectorString());

        filterChain.doFilter(request, response);
    }

    @Override
    public void init(FilterConfig filterConfig) {}

    @Override
    public void destroy() {}

}

SimpleResourceListener class

The SimpleResourceListener class is a service to demonstrate how changes in the resource tree can be listened for. It registers an event handler service and uses these annotations.

  • @Component – defines the class as a component
  • @Service - defines the service interface that is provided by the component

For information about these annotations, see http://felix.apache.org/documentation/subprojects/apache-felix-maven-scr-plugin/scr-annotations.html.

The following Java code represents the SimpleResourceListener class.

package com.aem.community.core.listeners;

import org.apache.felix.scr.annotations.Component;
import org.apache.felix.scr.annotations.Property;
import org.apache.felix.scr.annotations.Service;
import org.apache.sling.api.SlingConstants;
import org.osgi.service.event.Event;
import org.osgi.service.event.EventConstants;
import org.osgi.service.event.EventHandler;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * A service to demonstrate how changes in the resource tree
 * can be listened for. It registers an event handler service.
 * The component is activated immediately after the bundle is
 * started through the immediate flag.
 * Please note, that apart from EventHandler services,
 * the immediate flag should not be set on a service.
 */
@Component(immediate = true)
@Service(value = EventHandler.class)
@Property(name = EventConstants.EVENT_TOPIC, value = "org/apache/sling/api/resource/Resource/*")
public class SimpleResourceListener implements EventHandler {

    private final Logger logger = LoggerFactory.getLogger(getClass());

    public void  handleEvent(final Event event) {
        logger.debug("Resource event: {} at: {}", event.getTopic(), event.getProperty(SlingConstants.PROPERTY_PATH));
    }
}

Note:

For more information about an AEM Event Handler, see Creating Event Handlers for Adobe Experience Manager

HelloWorldModel class

The HelloWorldModel is a sample class that uses Sling Models. This class uses Sling Model annotations such as @Model. For information, see Sling Models

The following class represents the HelloWorldModel class. 

package com.aem.community.core.models;

import javax.annotation.PostConstruct;
import javax.inject.Inject;
import javax.inject.Named;

import org.apache.sling.api.resource.Resource;
import org.apache.sling.models.annotations.Default;
import org.apache.sling.models.annotations.Model;
import org.apache.sling.settings.SlingSettingsService;

@Model(adaptables=Resource.class)
public class HelloWorldModel {

    @Inject
    private SlingSettingsService settings;

    @Inject @Named("sling:resourceType") @Default(values="No resourceType")
    protected String resourceType;

    private String message;

    @PostConstruct
    protected void init() {
        message = "\tHello World!\n";
        message += "\tThis is instance: " + settings.getSlingId() + "\n";
        message += "\tResource type is: " + resourceType + "\n";
    }

    public String getMessage() {
        return message;
    }
}

Note:

For more information about working with Sling Models during AEM development, see Working with Sling Models in Adobe Experience Manager

SimpleScheduledTask class

This class is an AEM scheduler for cron-job like tasks that get executed regularly. It also demonstrates how property values can be set. Users can set the property values in /system/console/configMg. For more information about Sling Scheduler functionality, see Scheduler Service.

The following Java code represents this class. 

package com.aem.community.core.schedulers;

import java.util.Map;

import org.apache.felix.scr.annotations.Activate;
import org.apache.felix.scr.annotations.Component;
import org.apache.felix.scr.annotations.Properties;
import org.apache.felix.scr.annotations.Property;
import org.apache.felix.scr.annotations.Service;
import org.apache.sling.commons.osgi.PropertiesUtil;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * A simple demo for cron-job like tasks that get executed regularly.
 * It also demonstrates how property values can be set. Users can
 * set the property values in /system/console/configMgr
 */
@Component(metatype = true, label = "A scheduled task", 
    description = "Simple demo for cron-job like task with properties")
@Service(value = Runnable.class)
@Properties({
    @Property(name = "scheduler.expression", value = "*/30 * * * * ?",
        description = "Cron-job expression"),
    @Property(name = "scheduler.concurrent", boolValue=false,
        description = "Whether or not to schedule this task concurrently")
})
public class SimpleScheduledTask implements Runnable {

    private final Logger logger = LoggerFactory.getLogger(getClass());
    
    @Override
    public void run() {
        logger.debug("SimpleScheduledTask is now running, myParameter='{}'", myParameter);
    }
    
    @Property(label = "A parameter", description = "Can be configured in /system/console/configMgr")
    public static final String MY_PARAMETER = "myParameter";
    private String myParameter;
    
    @Activate
    protected void activate(final Map<String, Object> config) {
        configure(config);
    }

    private void configure(final Map<String, Object> config) {
        myParameter = PropertiesUtil.toString(config.get(MY_PARAMETER), null);
        logger.debug("configure: myParameter='{}''", myParameter);
    }
}

Note:

For more informatrion about using a Scheduler Service within AEM, see Scheduling Adobe Experience Manager Jobs using Apache Sling

SimpleServlet class

The SimpleServlet class represents a simple AEM servlet created using Apache Sling APIs. This servlet using resoure type binding to invoke the servlet. In this example, it binds to this resource: 

@SlingServlet(resourceTypes = "AEM62App/structure/page")

The following Java code represents the SimpleServlet class. 

package com.aem.community.core.servlets;

import org.apache.felix.scr.annotations.sling.SlingServlet;
import org.apache.sling.api.SlingHttpServletRequest;
import org.apache.sling.api.SlingHttpServletResponse;
import org.apache.sling.api.resource.Resource;
import org.apache.sling.api.servlets.SlingAllMethodsServlet;
import org.apache.sling.api.servlets.SlingSafeMethodsServlet;

import javax.servlet.ServletException;
import java.io.IOException;

/**
 * Servlet that writes some sample content into the response. It is mounted for
 * all resources of a specific Sling resource type. The
 * {@link SlingSafeMethodsServlet} shall be used for HTTP methods that are
 * idempotent. For write operations use the {@link SlingAllMethodsServlet}.
 */
@SuppressWarnings("serial")
@SlingServlet(resourceTypes = "AEM62App/structure/page")
public class SimpleServlet extends SlingSafeMethodsServlet {

    @Override
    protected void doGet(final SlingHttpServletRequest req,
            final SlingHttpServletResponse resp) throws ServletException, IOException {
        final Resource resource = req.getResource();
        resp.getOutputStream().println(resource.toString());
        resp.getOutputStream().println(
                "This content is generated by the SimpleServlet");
    }
}

Note:

For more information about creating an AEM servlet that binds to resources, see Binding Adobe Experience Manager Servlets to ResourceTypes

Modify the Maven POM file

Add the following POM dependencies to the POM file located at C:\AdobeCQ\echo62.

<dependency>
               <groupId>com.adobe.aem</groupId>
               <artifactId>uber-jar</artifactId>
               <version>6.2.0</version>
               <!-- for AEM6.1 use this version     : <version>6.1.0</version> -->
               <!-- for AEM6.1 SP1 use this version : <version>6.1.0-SP1-B0001</version> -->
               <!-- for AEM6.1 SP2 use this version : <version>6.1.0-SP2</version> -->
               <!-- for AEM6.2 use this version     : <version>6.2.0</version> -->
               <classifier>obfuscated-apis</classifier>
               <scope>provided</scope>
           </dependency>
            
           <dependency>
               <groupId>org.apache.geronimo.specs</groupId>
               <artifactId>geronimo-atinject_1.0_spec</artifactId>
               <version>1.0</version>
               <scope>provided</scope>
           </dependency>

When you add new Java classes under core, you need to modify a POM file to successfully build the OSGi bundle. You modify the POM file located at C:\AdobeCQ\echo62\core. This POM file appears in the root of the Eclipse project, as shown in the following illustration.  

POM
Project POM file

The following XML represents the POM file.

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>AEM62App</groupId>
        <artifactId>echo62</artifactId>
        <version>1.0-SNAPSHOT</version>
        <relativePath>../pom.xml</relativePath>
    </parent>
    <artifactId>echo62.core</artifactId>
    <packaging>bundle</packaging>
    <name>AEM62App  - Core</name>
    <description>Core bundle for AEM62App </description>
    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.felix</groupId>
                <artifactId>maven-scr-plugin</artifactId>
            </plugin>
            <plugin>
                <groupId>org.apache.felix</groupId>
                <artifactId>maven-bundle-plugin</artifactId>
                <extensions>true</extensions>
                <configuration>
                    <instructions>
                        <!--
                        <Embed-Dependency>
                            artifactId1,
                            artifactId2;inline=true
                        </Embed-Dependency>
                        -->
                        <Sling-Model-Packages>
                            com.aem.community.core
                        </Sling-Model-Packages>
                    </instructions>
                </configuration>
            </plugin>
        </plugins>
    </build>
    <profiles>
        <!-- Development profile: install only the bundle -->
        <profile>
            <id>autoInstallBundle</id>
            <activation>
                <activeByDefault>false</activeByDefault>
            </activation>
            <build>
                <plugins>
                    <plugin>
                        <groupId>org.apache.sling</groupId>
                        <artifactId>maven-sling-plugin</artifactId>
                        <configuration>
                            <!-- Note that this requires /apps/AEM62App/install to exist!!          -->
                            <!--    This is typically the case when ui.apps is deployed first                -->
                            <!--    Otherwise, create /apps/AEM62App/install manually (CRXDE|Lite)  -->
                            <slingUrlSuffix>/apps/AEM62App/install/</slingUrlSuffix>
                            <failOnError>true</failOnError>
                        </configuration>
                    </plugin>
                </plugins>
            </build>
        </profile>
    </profiles>
    <dependencies>

         <!-- OSGi Dependencies -->
            
        <dependency>
            <groupId>com.adobe.aem</groupId>
            <artifactId>uber-jar</artifactId>
            <classifier>obfuscated-apis</classifier>
        </dependency>
 
        <dependency>
            <groupId>org.apache.geronimo.specs</groupId>
            <artifactId>geronimo-atinject_1.0_spec</artifactId>
        </dependency>

        <!-- OSGi Dependencies -->
        <dependency>
            <groupId>org.apache.felix</groupId>
            <artifactId>org.apache.felix.scr</artifactId>
        </dependency>
        <dependency>
            <groupId>org.apache.felix</groupId>
            <artifactId>org.apache.felix.scr.annotations</artifactId>
        </dependency>
        <dependency>
            <groupId>biz.aQute</groupId>
            <artifactId>bndlib</artifactId>
        </dependency>
        <dependency>
            <groupId>org.osgi</groupId>
            <artifactId>org.osgi.core</artifactId>
        </dependency>
        <dependency>
            <groupId>org.osgi</groupId>
            <artifactId>org.osgi.compendium</artifactId>
        </dependency>
        <!-- Other Dependencies -->
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-api</artifactId>
        </dependency>
        <dependency>
            <groupId>javax.jcr</groupId>
            <artifactId>jcr</artifactId>
        </dependency>
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>servlet-api</artifactId>
        </dependency>
        <dependency>
            <groupId>com.adobe.aem</groupId>
            <artifactId>aem-api</artifactId>
        </dependency>
        <dependency>
            <groupId>org.apache.sling</groupId>
            <artifactId>org.apache.sling.models.api</artifactId>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
        </dependency>
        <dependency>
            <groupId>org.mockito</groupId>
            <artifactId>mockito-all</artifactId>
        </dependency>
        <dependency>
            <groupId>junit-addons</groupId>
            <artifactId>junit-addons</artifactId>
        </dependency>
    </dependencies>
</project>

Build the OSGi bundle using Maven

To build the OSGi bundle by using Maven, perform these steps:

  1. Open the command prompt and go to the C:\AdobeCQ\echo62 folder.
  2. Run the following maven command: mvn -PautoInstallPackage install.
  3. The OSGi component can be found in the following folder: C:\AdobeCQ\echo62\core\target. The file name of the OSGi component is echo62.core-1.0-SNAPSHOT.jar.

Note:

The command -PautoInstallPackage automatically deploys the OSGi bundle to AEM. 

Viewing the running OSGi bundle

After you deploy the OSGi bundle by using the Maven command, you can see it in an active state in the Adobe CQ Apache Felix Web Console.

Felix
The OSGi bundle in Active State

View your OSGi bundle by performing these steps:

  1. Login to Adobe CQ’s Apache Felix Web Console at http://server:port/system/console/bundles (default admin user = admin with password= admin).
  2. Click the Bundles tab, sort the bundle list by Id, and note the Id of the last bundle.

Understanding the UI Apps content

The Archetype 10 project creates default files under /apps, as shown in this illustration. 

AppFiles
Default files under /apps

The follownig list describes these files: 

  • A - default components that you can use in your project. You can also modify these components to meet your business requirements. 
  • B - files that create page content, inlcuding footers, top navigation, and so on. For example, you can find footer content in this file: /apps/AEM62App/components/structure/page/partials/footlibs.html. 
  • C - configuration information for the OSGi service. 
  • D - default i18n files 
  • E - defines two templates: page content and page home. 

Note:

The following sections explains these files in more detail. 

AEM62App default components

The following default components are created under components/content: 

  • helloworld - a basic component that displays text
  • image - a basic image component
  • text - a basic text component
  • textimage - a basic textimage component
  • title - a basic title component

helloworld component

The helloworld component is a basic HTL component that displays text. Notice the following code. 

<pre data-sly-use.hello="com.adobecq.community.core.models.HelloWorldModel">
HelloWorldModel says:
${hello.message}

The first thing to notice about this code is:

<pre data-sly-use.hello="com.adobecq.community.core.models.HelloWorldModel">

In this example, data-sly-use.hello references the Java class named HelloWorldModel. (This class is explained earlier in this article).   The HelloWorldModel uses Sling Models. This line of code:

${hello.message}

returns the value of the  getMessage method in the HelloWorldModel class. This value is displayed by the helloworld component. 

Note:

You can see the output of the helloworld component in the illustration shown at the start of this development article. 

Note:

For more information about using HTL with AEM, see this article (this article also references other HTL content), Creating your first Adobe Experience Manager HTL component

image component

The image component is a basic HTL component that displays an image, as shown in this illustration. 

Iamge
The default image component

If you look under components/content/image, you will not see any code for the component. This is because this component inherits from the main image component. This is made possible by setting the component's sling:resourceSuperType property to wcm/foundation/components/image. This is how component inheritence works with AEM.

For more information about component inheritence, see AEM Components - the Basics.

text component

The text component lets an author enter text into an AEM web page. Like the image component, this component inherits from the main component by setting the sling:resourceSuperType property to wcm/foundation/components/text

textimage component

The textimage component lets an author enter text and an image into an AEM web page. Like the image component, this component inherits from the main component by setting the sling:resourceSuperType property to wcm/foundation/components/textimage

title component

The title component lets an author enter a title into an AEM web page. Like the image component, this component inherits from the main component by setting the sling:resourceSuperType property to wcm/foundation/components/title

AEM62App structure components

Under /apps/AEM62App/components/structure, there are additional components. Notice the page component, as shown here. 

Page
Default files for the Page component

The page component is a HTL component that references the other files (under the partials folder) by using the sly data-sly-include statement. 

<html lang="en">
    <head>
        <sly data-sly-include="partials/head.html" data-sly-unwrap/>
        <sly data-sly-include="partials/headlibs.html" data-sly-unwrap/>
    </head>
    <body class="page ${currentPage.template.name}">
        <sly data-sly-include="partials/main.html" data-sly-unwrap/>
        <sly data-sly-include="partials/footlibs.html" data-sly-unwrap/>
    </body>
</html>

For example, notice that the footlibs.html file is at the bottom. This represents the page's footer. The following code shows this file. 

<!--/* Include the site client libraries (loading only the JS in the footer, CSS was loaded in the header) */-->
<sly data-sly-use.clientLib="/libs/granite/sightly/templates/clientlib.html" data-sly-call="${clientLib.js @ categories='AEM62CSS.all'}" data-sly-unwrap/>

<!--/* Include Adobe Dynamic Tag Management libraries for the footer */-->
<sly data-sly-resource="${@ resourceType='cq/cloudserviceconfigs/components/servicecomponents'}" data-sly-unwrap/>

In this example, notice data-sly-use.clientLib. This is how you reference an AEM clientlib in AEM. In this example, it is referencing /libs/granite/sightly/templates/clientlib.html. However, you can reference your own client libs folder tha contains other JavaScript libraries that you want to use in your AEM project.

To see an example of using ClientLibs, see this article: Creating an AEM HTL tab movie component.

Note:

Look at the source code of the other files under the partial folder. 

Default ClientLibs for AEM62App

The Archetype 10 project create a default clientlib location for your AEM project. This clientlibs folder is located at the following location:

/etc/designs/AEM62App

If you need to add additional CSS or JS files to your project, you can add them there. WHen you package up your project, include this folder as well.

To see an example of a JQuery lib being added to this clientlibs folder for an AEM project, see this article: 

Creating an AEM Headline component

Running the default web page

You can view the default web page by using the following URL: 

http://localhost:4502/content/AEM62App/en.html

Notice that this page displays the HelloWorld component. 

See also

Congratulations, you have just created an AEM project using an Archetype 10 project. Please refer to the AEM community page for more articles that discuss how to build AEM services/applications.

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